In response to the occurrence of defects such as shrinkage and porosity during the casting process, which lead to stress concentration under high load conditions, produce local high stress-strain zones and local yielding, resulting in reducing the service life of the parts. By using a combination of finite element simplified modeling and experimental analysis verification, the effects of the distance between micropores and the free surface, the distance between the pores, the porosity morphology and the distribution angles on the stress concentration in A356 cast aluminum alloys are systematically studied. The relationship between the influence of each defect feature on the stress-strain concentration is established, and the established relationship is verified by actual pores in the sample.

With the aluminum alloy door of passenger car as the research object, the laser wire filling welding process and welding quality of aluminum alloy sheet are studied through comprehensive application of simulation and process test. The optimal process parameters suitable for laser wire filling welding of aluminum alloy door are obtained by judging the forming quality and mechanical properties of the weld after welding. Using this parameter, the laser wire filling welding of the inner plate assembly of the aluminum door is prototyped and a better welding quality is achieved. The results show that for the laser wire filling lap welding of 5182 aluminum plate and 6016 aluminum plate with thickness of 1.5 mm, better weld forming quality and mechanical properties can be obtained with the following process parameters: 2 600 W laser power, 2.5 m/min welding speed and 7 m/min wire feeding speed, and can satisfy the welding quality requirements of the actual aluminum door inner plate assembly.

To get reliable forming process parameters for aluminum products, the inner panel of an automotive aluminum door is taken as the research object. Considering the structural characteristics of this product, the process modeling and analysis are initially performed using the AutoForm software to identify the risk areas of its forming defects. Subsequently, the blank size, binder force, and the resistance coefficient of the drawbead are adopted as the design variables for process optimization. The process optimization analysis is implemented through the Sigma module. After a cumulative total of 114 iterative operations, the optimal parameter combination that complies with the forming quality evaluation criteria is obtained. Production verification shows that the formed quality of the stamped parts is excellent according to the optimal parameter combination.

In order to explore the effect of annealing process on the properties and microstructure of 3003 aluminum alloy for lithium battery of new energy vehicle, the evolution characteristics of room temperature mechanical properties, hardness, cupping value, earing rate and microstructure of 3003 aluminum alloy for lithium battery of new energy vehicle after annealing at different temperatures (150 ~ 500 ℃) and holding for 3 h are studied by means of electronic universal testing machine, hardness tester, cupping test machine, forming test machine and optical microscope. The preferred experimental annealing process of 3003 aluminum alloy is determined. The results show that the best combination of mechanical properties, formability and microstructure of 3003 aluminum alloy is obtained when the annealing temperature is 400 ℃ and the holding time is 3 h. This annealing process is applied to the box-type annealing furnace on the production site for verification, which is in good agreement with the test results.

To solve the quality issues that rear quarter PVC residue interference with assembly shop installation, PVC material, nozzle temperature and robot application program are optimized as following. For PVC material, Relevant viscosity and yield value with the precondition of no influence to the tightness and appearance are increased; The nozzle temperature is reduced and the PVC residue amount is decreased; The gun on-and-off points of rear quarter are cancelled and two adjacent seams are combined to one big seam. The result indicates that the solutions above remove the PVC residue on rear quarter and avoid the PVC interference to assembly installation surface.

Based on the existing wet spray booth scrubber system in the domestic automotive manufacturing industry, this study analyzes the wet eliminator to dry carton system proposal, modifies the exit structure and develops the targeted solutions according to different building height,spray booth width, layout and surroundings. At the same time, simulation software is used to simulate and optimize the field flow, in order to shorten modification cycle, reduce the investment cost and optimize the equipment.

This study first compared the material properties and costs to determine the use of 45% by mass glass fiber (GF) reinforced nylon (PA). Based on the envelope, electrical performance, and insulation requirements given by the battery system,the structural design scheme of the integrated insulation structure battery housing has been determined. CAE analysis was conducted on this housing with integrated insulation structure. Equal proportion samples of the composite housing were manufactured using LFT-D technology and the insulation structure was integrated. Corresponding CFD analysis and insulation performance testing were carried out; Simulation analysis and sample testing have proven that the mechanical and insulation properties of this housing meet the design specifications, and compared to aluminum alloy housing, the housing also has the advantages of lightweight and low cost.

In order to study the influence of sound absorption factors on automobile headliner, impedance tube is used to test the sound absorption characteristics of automotive headliner materials based on the transfer function method; the flow resistance of the headliner is tested based on the direct current method, to analyze the effects of production process, fabric, PU, glue and flow resistance on the sound absorption of the headliner. The results show that the production process, fabric layer and PU are the main factors affecting the sound absorption factors on the headliner. The sound absorption coefficient of the two-step production process is increased by 0.1~0.45 in the frequency range above 1 000 Hz; the sound absorption coefficient of knitted fabric is higher than non-woven fabric by 0.05~0.29 in the whole frequency range. Above the 1 000 Hz frequency, when the thickness or density of PU is increased, the sound absorption coefficient is increased by 0.02~0.43, and the peak of sound absorption is close to 1. The average sound absorption coefficient increases with the flow resistance. Reasonable selection of headliner with high flow resistance can effectively increase the resistance of sound wave propagating in the material, which is conducive to rapid attenuation of sound energy and improvement of sound absorption effect.

Microstructured materials are increasingly favored due to their excellent performance. This paper introduces the concepts, principles and configurations of microstructured materials, it lists common types of microstructured materials, including porous metals, porous ceramics, foamed plastics, sandwich materials, etc., analyzes their applications in automotive safety, NVH and thermal management, describes and prospects the development concept of material-structure-function integrated product.

In order to rationally plan workshop layout, this paper proposes an assembly workshop layout planning method based on genetic algorithm. A mathematical model of workshop layout planning is constructed by linear programming, and the model is solved by genetic algorithm, then assembly workshop of an enterprise is taken as example to verify effectiveness of the model. The research findings indicate that the proposed method can effectively address the workshop layout problem resulting from logistics upgrading, which presents a general solution for the workshop layout planning in discrete manufacturing enterprises under similar circumstances.

This paper introduces system composition, basic measurement principle and system control principle of the in-line measurement system used in BBAC body shop flexible production line, and defines the commissioning requirements for system accuracy guarantee to realize the calibration and compensation of dimensional measurement values. The use of the visual management system IQVIS further assists the body shop to quickly and efficiently analyze the dimensional accuracy of the body in white and predict the changing trend. By setting the out-of-tolerance alarm function, the intelligent management and quality control of the three-level tolerance of the body dimension can be realized, which can significantly reduce the impact of defective body on the subsequent processes.